Bias is a systematic error that can cause distorted results leading to incorrect conclusions. Intervention bias (i.e., contamination bias, cointervention bias, compliance bias, and performance bias) and detection bias are the most common biases in rehabilitation research. A better understanding of these biases is essential at all stages of research to enhance the quality of evidence in rehabilitation trials. Therefore, this narrative review aims to provide insights to the readers, clinicians, and researchers about contamination, cointervention, compliance, performance, and detection biases and ways of recognizing and mitigating them. The literature selected for this review was obtained mainly by compiling the information from several reviews looking at biases in rehabilitation. In addition, separate searches by biases and looking at reference lists of selected studies as well as using Scopus forward citation for relevant references were used.This review provides several strategies to guard against the impact of bias on study results. Clinicians, researchers, and other stakeholders are encouraged to apply these recommendations when designing and conducting rehabilitation trials.
The objective of this review was to summarize the concept of clinical significance and associated methods focusing on the area of rehabilitation to provide a resource to rehabilitation researchers and clinicians. Studies were searched on electronic databases from inception until July 28, 2020, with no date or language limits. Manual searches as well as Scopus forward citation for relevant references were performed. Narrative synthesis of study results was performed. Definitions of the concepts related to clinical significance, ways of calculating, and interpreting each method were provided using rehabilitation examples. An explanation of methods to evaluate clinical significance (distribution, anchor, and opinion-based methods) and their advantages and disadvantages were also provided. Considering the limitations of statistical significance in assuring meaningfulness of results, clinical interpretation of research outcomes and the report of clinical significance in intervention trials should be a priority in rehabilitation research. When possible, the use of multiple methods (distribution, anchor, and opinion based) is recommended. Thus, clinical researchers are encouraged to present results in a manner that allow the rehabilitation professionals to easily interpret and implement those results in their clinical practice.